Pure fluid amplifier



July 1s, 19

Original Filed Dec. 17, 196

B. M. HORTON PURE FLUID AMPLI FIER 2 Sheet s-Sheet l ,5/4 L y M Hoera/vATTORNEYS.

`July 18, 1997 B. M. Hom-0N 3,33,382

PURE FLUID AMPLIFIER Original Filed Deo. 17, 1965 2 Sheets-Sheet 2INVENTOR,

UnitedStates Patent O 3,331,382 PURE FLUID AMPLIFIER Billy M. Horton,Kensington, Md., assigner to the United States of America as representedby the Secretary of the Army Continuation of application Ser. No.331,328, Dec. 17, 1963. This application May 26, 1966, Ser. No. 554,2827 Claims. (Cl. 137-815) This application is a continuation of myapplication Ser. No. 331,328 filed Dec. 17, 1963, and now abandoned, forPure Fluid Amplifier.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment to me ofany royalty thereon.

This invention relates generally to pure duid amplifying systems andmore specifically to a pure uid amplifier which has the bias and thesensitivity thereof established and controlled by rotating orcirculating uid input signals.

Typically, pure uid amplifiers; that is, fiuid amplifiers which amplifythe momentum of an input signal without any moving mechanical parts areformed by a sandwichtype structure consisting of an upper plate and alower plate which serve to confine fiuid ow to a planar ow patternbetween the two plates. The pure uid amplifier includes a main or powernozzle which extends through an end wall of an interaction chamber orregion, the interaction chamber also being formed by two sidewalls(hereinafter referred to as the left and right sidewalls). One or moreiiow dividers disposed at a predetermined distance or distances from theend wall, and the leading edges or surfaces of the dividers are disposedrelative to the main iiuid nozzle centerline so as to define separateareas in a target plane. The sidewalls of the dividers in conjunctionwith the interaction region sidewalls establish the receiving apertureswhich are entrances to the amplifier output channels. Completing thedescription of the pure fiuid amplifier, left and right control orificesmay extend through the left and right sidewalls respectively. In thecomplete unit, the region bounded by top and bottom plates, sidewalls,the end wall, receiving apertures, dividers, control orifices and a mainfluid nozzle, is termed an interaction chamber region.

Two broad classes of pure uid amplifiers are (I) Stream interaction(momentum exchange) `or continuously variable control pressure devicesand (II) Boundary Layer Control devices. Class I amplifiers includedevices, in distinction to the devices of Class Il, in which there islittle or no interaction between the side walls of the interactionregion and the power stream. Power stream deflection in such a unit iscontinuously variable in accordance with control signal amplitude thesignal constituting a flow (or flows) which interacts with the powerstream to deflect it as a result of momentum interchange between thestreams and/ or which controls the relative pressures in the regions onopposite sides of the power stream. Such a unit is referred t-o as acontinuously variable amplilier or computer element. In an amplifier orcomputer element of this type, the detailed contours of the side wallsof the interaction chamber are of secondary importance to theinteracting forces ybetween the streams themselves. Although the sidewalls of such units can be used to contain fluid in the interactingchamber, and thus make it possible to have the control ow effect thepower stream in a region at some desired ambient pressure, the sidewalls are so placed that they are somewhat remote from the high velocityportions of the power stream so that it does not approach or attach tothe side walls. Under these conditions the power stream flow pat-Patented July 18, 1967 lCe tern within the interacting chamber dependsprimarily upon the size, speed and direction of the power streamrelative to the control flow and upon the density, viscosity,compressi'bility and other properties of the uids employed.

(II) The second broad class of fluid amplifier and computer elementscomprises units in which the main power stream flow and the surroundingiiuid interact in such a way with the interaction region side walls thatthe resulting ow patterns and pressure distributions Within theinteraction region are greatly affected by the details of the design ofthe chamber walls. In this broad class of units, the powerstream mayapproach or may Contact the interaction region side walls. The effect ofthe side wall configuration on the ow patterns and pressuredistribution, which can be achieved with single or multiple streams,depends upon the relation between: the width of the interaction chambernear the power nozzle, the width of the power nozzle, the position ofthe center line yof the power nozzle relative to the side walls(symmetrical or asymmetrical), the angles that the side walls make withrespect to the center line of the power nozzle; the length of the sidewalls or their effective length as established by the spacing betweenthe power nozzle exit and the flow dividers, side wall contour and slopedistribution; and the density, viscosity, compressibility and uniformityof the fluids used in the interaction region. It also depends on theaspect ratio, i.e. the ratio of the' height to the width of the powernozzle, and therefore to some extent on the thickness of the amplifyingor computing element in the case of two-dimensional units. Theinterrelationship between the above parameters is quite complex and isdescribed subsequently. Response time characteristics are a function ofsize of the units and the density of the fluid and operating pressure.

Amplifying and computing devices of this second broad category whichutilize boundary layer effects; i.e., effects which depend upon detailsof side wall configuration and placement, can be further subdivided intothree sub-types:

(a) Boundary layer units in which there is no lock on effect.

(b) Boundary layer units in which lock on effects are appreciable.

(c) Boundary layer units in which lock on effects are dominant and whichhave memory.

Sub-type (a) Boundary layer elements in which there is no lock oneffect: Such a unit has a gain as a result of boundary layer effects.However, these effects do not dominate the control signal but insteadcombine with the control -tiows to provide a continuously variableoutput signal responsive to control signal amplitude. In these units thepower stream remains diverted from its initial direction only if thereis a continuing iiow out of or into one or more of the control orifices.

Sub-type (b) Boundary layer units in which lock on effects areappreciable: In these units, the boundary layer effects are sufiicientto maintain the power stream in a particular deliected flow patternthrough the action of the pressure distribution arising fromasymmetrical boundary layer effects and require no additional streams,other than the power stream to maintain that flow pattern. Naturally inthis type unit continuous application of a control signal can also beused to maintain a power stream fiow pattern. Such iiow patterns can bechanged to a new stable ow pattern, however, either by supplying orremoving fluid through one or more of the control orifices, or through acontrol signal introduced by altering the pressures at one or more ofthe output apertures, as for example by blocking of the output channelto which iiow has been directed.

Sub-type (c) Boundary layer control units which have memory, i.e.,wherein lock-on characteristics dominate type boundary layer units, theflow pattern can be maintained through the action of the power streamalone without the use ofV any other stream or continuous application ofa control signal. ln these units, the flow patternV can be modified bysupplying or removing fluid through one or more of the appropriatecontrol orifices. However, certain parts of the power stream flowpattern, including lock-on to a given side wall, are maintained eventhough the pressure distribution in the output channel to which flow isbeing delivered is modified, even to the extent of completely blockingthis output channel.

The power stream deflection phenomena in boundary layer units is theresult of a transverse pressure gradient due to a difference in theeffective pressures which exist between the power stream and theopposite interaction region side walls; hence, the term Boundary LayerControl. In order to explain this effect, assume initially that thefluid stream is issuing from the main nozzle and is directed toward theapex of a centrally located divider. The fluid issuing from the nozzle,in passing through the chamber, entrains some of the surrounding fluidin the adjacent interaction regions and removes this fluid therefrom. lfthe fluid stream is slightly closer to, for instance, the left side wallthan to the right side wall, it is more effective in entraining andremoving the fluid in the interaction region between the stream and theleft wall than it is in entraining and removing fluid between the streamand the right wall since the former region is smaller. Therefore, thepressure in lthe left interaction region between the left side wall andpower stream is lower than the pressure in the right interaction regionand a differential pressure is set up across the power jet tending tode- ;flect it towards the left side wall. As the stream is deflectedfurther toward the left side wall, it becomes even more efficient inentraining fluid from the left interaction region and the effectivepressure in this region is further reduced. In those units which exhibitlock-on features or characteristics, this feedback-type action isself-reinforcing and results in the fluid power stream being deflectedtoward the left wall and predominantly entering the left receivingaperture and outlet channel. The stream attaches to and is then directlydeflected by the left side wall as the power stream'eifectivelyintersects the left side Wall at a predetermined distance downstreamfrom the outlet of the main orifice; this location being normallyreferred to as the attachment location. This phenomena is referred to asboundary layer lock-on. The `operation of this type of apparatus may becompletely symmetrical in that if the stream had initially been slightlydeflected toward the right side wall rather than the left side wall,boundary layer lock-on would have occurred against the right side wall.

Control of these units can be effected by controlled flow of fluid intothe boundary layer region from control orifices at such a rate that thepressure in the associated boundary layer region becomes greater thanthe pressure in the opposing boundary layer region located on theopposite side of the power stream and the stream is switched towardsthis opposite side of the unit.

Alternatively instead of having flow into the boundary layer region tocontrol the unit, fluid may be withdrawn from `this opposite controlorifice to effect a similar control by lowering the pressure on thisopposite side of the stream instead of raising the pressure on the firstside. The control flow may be at such a rate and volume as to deflectthe power stream partially by momentum interchange so that a combinationof the two effects my be employed. However, it is not essential, and inmany cases is undesirable, that the control flow have a momentumcomponent transverse to the power stream when the control fluid issuesfrom its control orifice.

Only a small amount of energy is required in the control signal fluidflow to alter the power jet path so that some or all of the power jetbecomes intercepted by the load device or output passage. For acontinuously applied control signal, the power gain of this system canbe considered equal to the ratio of the change of power delivered by theamplifier to its output channel or load to the change of control signalpowerV required to effect this associated change of power delivered tothe output channel or load. Similarly, the pressure gain can beconsidered equal to ratio of the change 0f output pressure to the changeof control pressure required to cause the change; or, the ratio of thechange of output channel mass flow rate to the associate change ofcontrol Signal mass flow rate required defines the mass flow rate gain.

lt is apparent that this second broad class of pure fluid amplifiers andcomponents and systems provide units which can be interconnected withother units (for example, either class I or VII elements) so that theoutput signal of one unit can provide the control or power jet supply ofa second unit. Since each stage can have a gain greater than unity, agiven stage can be used to drive a larger second stage, or severalsecond stages each of which is the same size as the first.

The term input signal is defined as the fluid signal which isintentionally supplied to the fluid component for the purpose ofinstructing or commanding that component to provide a desired outputsignal. The term output signal used herein is the fluid signal which isproduced by the fluid component. The input and output signals can be inthe form of time or spatial variations in pressure, density, flowvelocity, mass flow rate, fluid composition, transport properties, orother thermodynamic properties of the input fluid, individually or incombination thereof. The term fluid as used herein includes compressibleas well as incompressible fluids, fluid mixtures and fluid combination,and suspensions of solid particles in a fluid.

The present invention is directed primarily to an arrangement forintroducing control signals into pure fluid systems and is equallyapplicable to both of the classes and to the sub-classes of fluidamplifiers set forth above. rthe invention provides apparatus forintroducing control signals in such a way as to minimize turbulenceresulting from interaction between power .and control fluid flowsthereby providing smoother and steadier flow patterns of lower noiselevels and of greater long term stability than otherwise might beavailable.

More particularly, cont-rol signals Iare introduced into the system bymeans of flow directed generally parallel to the flow of the main orpower stream.

The con-trol nozzle takes the for-m of a substantially cylindrical orspiral-shaped chamber which is positioned essentially t-angentially tothe sidewalls of the'interaction chamber, the cylindrical orspiral-shaped chamber communicating with the interaction chamber througha port formed essentially at the point of tangency. The power streamflowing across the port of the cylindrical chamber causes `a momentuminterchange to occur between the power stream and the fluid in thecylindrical chamber..

This momentum interchange takes place because of the lviscous effectswithin the fluid and because of turbulent mixing. The momentuminterchange which occurs causes some of the fluid in the chamber to beentrained in power stream thereby reducing the pressure in the chamberand further produces rotation or circulation of the fluid in thesubstantially-cylindrical chamber, further varying the pressuredistribution therein. By varying or governing the internal feed of fluidto the center and/ or flow from the periphery of the cylindrical controlnozzles, it is possible to control the pressures on opposite sides ofthe power stream and therefore control its displacement relative to theoutput channels. This type of arrangement is equally applicable to classl and class II amplifiers. In class I devices the control flowsestablish a power stream position which is a function of the relativeflows to and/or from the control nozzles. ln the class II devices,switching of.

tems are typically constructed of two or three flat plates sandwichedytogether and held in a fluid-tight relationship by machine screws,clamps, adhesives or any other suitable means. If only two flat platesare used, the passages, cavities and orifices needed to form the fluidamplifier component are cre-ated in one plate by etching, molding,milling, casting or other conventional techniques, and the other plateis sealed to the one plate to cover these passages, cavities andorifices. When the sandwich type structure comprises three plates, thecenter plate usually is cut out or shaped by other means to provide thedesired configuration of the fluid yamplifier component and theremaining two plates provide upper and lower covering plates forsandwiching and sealing the center plate therebetween.

Although conventional techniques for forming cavities, passages andorices are capable of providin-g relatively close dimensionaltolerances, the fluid output in the amplifying system oftentimesreflects slight dimensional deviations in either the size, shape orposition of the elements forming the system from the true designdimensions. For example, in the absence of an input signal, deviationsin the dimensions of the passages, cavities or orifices from thedetermined design dimensions may cause the system to have an inherentbias so that the flow or pressure pattern in the output passages iseither undesirably asymmetrical or undesirably symmetrical in comparisonto the desired ow or pressure pattern. If the system were to provide anull bias output signal from the output passages in the absence of acontrol signal, an unequal ilow or pressure condition in these passageswould be undesirable, whereas if a bias output signal were desired equalflow or pressure in the output passages would be undesirable. In eitherinstance, it is usually important that the bias of the particular fluidvamplifier be either present or absent, and in any event be known tothose who wish to use the system either as a single component or incombination with other pure fluid components, or with other types offluid systems.

The amount of bias in a particular pure fluid amplifying system may bereadily yascertained by applying a power stream to the power nozzle ofthe amplifier and sensing the differentials in mass flow, energy orpressure from the output passages by suitable fluid sensing instruments.Since this determination is preferably made after the plates have beensealed in duid-tight relation, one to the other, the problem thenyarises of being able to -increase, decrease or eliminate the bias ofthe system.

Hitherto, when a pure fluid component was found to be undesirablybiased, the component would be discarded as a reject because knownmethods for correcting this condition involved excessive expenditures oftime and effort. Those working in the art will appreciate the problemsof initially locating the -reason for the bias condition and thereafterattempting to correct the condition. When the plates are bonded togetherby a high-pressureresistant adhesive, they ordinarily cannot beseparated without changing or destroying their shapes and thus thepossibility of being able to satisfactorily separate the plates so thatthey could be used again is unfeasible. Thus, there appeared to be nosolution to the problem of eliminating the bias of, or providing adesired bias to, the enclosed pure fluid system in the absence of acontrol stream flow a control nozzle.

In addition, it is generally desirable to provide a pure fluid amplifierthat possesses at least some predetermined sensitivity to control inputsignals so that the magnitude of lthe control input sign-al -required todisplace the power stream through a given angle will be either known orpredictable.

In accordance with a further feature of the present invention, biascontrol may be effected by control of flow to and/or from the controlnozzles to vary the initial position of the power stream. Such controlmay be employed in a class I or class II a system to establish initiallya center position or somewhat deected position of the power stream inaccordance with the desired operating characteristics of the system. Inclass II b and C types, the present invention may be employed to causethe device to assume a predetermined state on start-up. In controllinginitial bias of the power stream, the apparatus also provides control ofsensitivity of the device. Establishing initial control flows alsoestablishes changes of ow in one nozzle required to produce a specificchange in power stream position relative to the initial positionresultingr at least partially for the initial flow in the other controlnozzle.

It is an object of the invention to provide a pure fluid amplifier,wherein the bias and sensitivity thereof is governed by flow which isrotating tangentially to the power stream and interacting therewith.

More specifically, it is an object of this invention to provide a purefluid amplifier, wherein the power stream generates a rotating controlstream by momentum interchange, and wherein the rotating control streameffects an amplified directional displacement of the power stream in thepure fluid amplifier.

Another 4object of this invention is to provide a fluid amplifier inwhich energy losses are minimized by providing a geometrical shape whichpermits a smooth circular flow pattern in the interaction region of `thestreams.

Another object of this invention is to provide a pure fluid amplifierincluding a power nozzle, an interaction chamber for receiving fluidegressing from the power nozzle, and a substantially-cylindrical controlnozzle located tangentially of the interaction chamber having an openingacross which the power jet issuing from the power nozzle can flow andthereby generate circulating fluid ow in the substantially-cylindricalchamber, the circulating flow in the substantially-cylindrical chambercontrolling the displacement of the power stream in the interactionchamber 'by momentum interchange, lor by supplying uid to control thefluid pressure in the boundary layer region in the interaction chamber.

Still another object of the present invention is to provide controlfluid flow to the interaction region of a fluid amplifier in such amanner that turbulent mixing of fluids is minimized and laminar flow ismaximized.

The above and still further objects, features and advantages `of thepresent invention will become apparent upon consideration of thefollowing detailed description of several specific embodiments thereof,especially when taken in conjunction with the accompanying drawings,wherein:

FIGURE 1 illustrates one embodiment of a pure fluid amplifierconstructed in accordance with this invention;

FIGURE la is a side View of the pure fluid amplifier shown in FIGURE l;

FIGURE 2 illustrates another embodiment of a pure fluid amplifierconstructed in accordance with this invention;

FIGURE 3 illustrates yet another embodiment of a pure fluid amplifier inaccordance with the instant invention.

Referring now to FIGURE l of the accompanying drawings for a morecomplete understanding of the invention, there is shown a pure fluidamplifier 10 formed between a pair of flat plates 11 and 12 which aresealed one to the other by machine screws, adhesives, -or other suitablemeans. The configuration defining the pure fluid amplifier 10 is formedin the flat plate 11 and the plate 12 covers the plate 11 in afluid-tight relationship. The pure fluid amplifier 10 includes a powernozzle 13, a pair of what will hereinafter be referred to as controlnozzles 14 and 15 of substantially cylindrical shape and ofsubstantially the same size that communicate by means of ports 16 and17, respectively with the sidewalls 18 and 19 of an interaction chamber20. The control nozzles 14 and 15 are positioned substantiallytangentially to the sidewalls 18 and 19 and the ports 16 and 17 arepreferably located opposite each other and at the points ofapproximately tangency. Located downstream of the interaction Vchamber2U is a flow splitter 23 and a pair of output passages 24 and 25,respectively, which receive fluid from the interaction chamber 2t?.Fluid enters the control nozzles 14 and 15 through substantiallycentrally located orifices 26 and 27, respectively, which have tubes ASand 29, respectively, threadedly connected therein. The diameters of theorifices 26 and 27 are preferably equal and considerably less than thediameters of the control nozzles 14. and 15 so that a planar base oflarge radius is provided in the nozzles 14 and 15 upon which therotating fluid can flow. Fluid may be supplied to the tubes 28 and 29 inorder to vary the amount of fluid within the control nozzles 14 and 15.

The power nozzle 13 is supplied fluid by means of a tube 31 which isthreadedly connected to a bore 32 formed in plate 12, the bore 32communicating with the input end of the control nozzle 13, as shown.Fluid supplied to the tube 31 is constricted by the configuration of thepower nozzle 13 and issues as a defined power stream into theinteraction chamber 2f). Assuming that the control nozzles 14 and 15communicate with sources of fluid, the power stream which is constrictedby the sidewalls 18 and 19 flows across the ports 16 and 17 and amomentum interchange is created between uid present in the controlnozzles 14 and 15 and the fluid at the edges or fringes of the powerstream. Some of the fluid is entrained in the main power stream therebyreducing the pressure at the ports 16 and 17. Other portions of thefluid are caused to move but remain in the nozzle 14 and due to viscousdrag produce rotation of the fluid in the control nozzles 14 and 15 inthe directions indicated by the arrows. Y

As the rotation in nozzle 14 increases, there is produced a differencebetween the static pressure at the outside edge of nozzle 14 and thestatic pressure at the entrance of the port 26 into the nozzle 14. Thisdifference in static pressure within the nozzle is brought about by thecentrifugal forces associated with the rotation mass of Vfluid in nozzle14. Thus the static pressure at the port 26 is less than the staticpressure at the outside edge of the nozzle 14 and therefore the staticpressure at the port 26 is less than the static pressure at the port 16.Thus the rotation of the fluid in nozzle 14 tends to draw fluid throughtube 28 into nozzle 14 to equalize the pressure in the nozzle and alsoto supply the entrainment fluid. The rotation of fluid in the nozzle 14also permits the -fiuid flowing through the port 26 to be introducedinto the interaction chamber Ztl in such a way that velocity gradientstransverse to the power stream issuing from the nozzle 13 are minimized.Thus one advantage of this pure fluid amplifier is that the tendency forturbulent mixing to occur is reduced, and since turbulent mixing ofstreams causes more loss of energy than laminar mixing, this way ofintroducing control fluid provides a fluid amplifier of greaterefficiency.

A further advantage of this type of nozzle is that it permits the use ofcontrol fluid at a lower pressure than if the control stream werebrought into the interaction region at a right angle to the powerstream. In a similar manner the rotation of fluid in nozzle 15 causesthe static pressure in port 27 to be less than the static pressure atport 17 and along the outside edge of nozzle 15. Thus the rotation tendsto draw in more fluid through tube 29 than if the fluid were brought inat a right angle to the power stream issuing from nozzle 13. Here againthe control fluid passing through port 17 is introduced into chamber 26with a velocity in the direction of flow of Vthe power streampreducingthe velocity gradients transverse to the power stream.

The displacement of the power stream in the interaction chamber 2t? isgoverned by a differential in static pressure developed transversely ofthe power stream as it crosses the ports 14 and 15. Increases ordecreases in the static pressure is governed by varying the amount ofuid supplied to the control nozzles 1-4 and 15 through the orifices 26and 27 respectively. Thus the position of the stream relative to theflow divider 23 is a function of relative amounts of fluid suppliedthrough pipes 23 and 29. These flows may be employed as indicated aboveto amplify input function and/or to control bias and sensitivity of theunit. Regulation of the quantity of fluid supplied to the controlnozzles 14 an-d 15, can be made externally of the fluid amplifier 10 bymeans of valves 33 and 34 or by means of pure fluid elements disposed inthe pipes.

In operation, if a relatively greater amount of fluid is supplied to thecontrol nozzle 14 than to the Control nozzle 15 by regulation of thevalves 33 and 34, respectively, the power stream will be displacedcloser to the sidewall 18 than towards the sidewall 19. The quantitiesof flows supplied initially determine the bias of the unit and thesensitivity of the power stream to control fluid signals superimposedupon the bias flows initially supplied. As will be evident to thoseworking in the art, it is therefore a relatively easy matter to providean initial bias and sensitivity .to the power stream and thereaftersuperimpose or apply a control fluid input signal to the fluid in thetubes 28 and 29 to effect amplified displacement of the power streamrelative to the upstream entrances to output passages 24 and 25,respectively.

The sidewalls defining the output passages 24 and 25 may also be setback relative to the openings 16 and 17, respectively as indicated bythe dotted lines 36 and 37 so that the combined power and controlstreams will tend to attach to either of the walls indicated by thenumerals 3e land 37, of the output passages 24 and 25, respectively, andbe displaced therefrom by fluid issuing into the point of attachmentfrom the -control nozzles 14 and 15, respectively. Thus, the pure fluidamplifier 1t) may also be a class II type pure fluid amplifier asdiscussed hereinabove. lf the sidewalls are set back the pressure in thecontrol nozzles will be further reduced. The pressure reduction causedby the centrifugal action of the rotating fluid will add to the pressurereduction -caused by setting back the walls as shown by the dotte-dlines in FIGURE l. i

FGURE 2 illustrates a pure fluid amplifier designated by numeral 191,which is a modilicationof the pure fluid amplifier 1li illustrated inFIGURE l. In the pure fluid amplifier -1, the cylindrical controlnozzles 141 and 151 are provided with cusps 41 and 42, respectively,which are designed to scoop off fringe portions of the circulating flowinto the passages 43 and 44, respectively, that extend tangentially fromthe periphery of the control nozzles 141 and 151, respectively. Tubes 46and 47 which may incorporate valves 4S and 49, respectively,

are threadedly connected to the downstream end of the` passages 43 and44, respectively. The valves 48 and 49 may be used to vary the amount offluid which egresses from the passages 43 and 44 and thereby vary theback pressure in the circular control nozzles 141 and 151. In thisembodiment, as in the embodiment illustrated'in FIGURE l of theaccompanying drawings, and discussed in detail hereinabove, thecirculation induced in the nozzles 141 and 151 by the power stream, indire-ctions indicated by the arrows, may be utilized to control theposition of the power stream in the interaction chamber 181. Inaddition, the power stream position may be controlled by backloading ofthe passages 43 and 44 by pure fluid systems to which the tubes 46 andY47 are connected or by backloading with other types of fluid or nonfiuidsystems; and the `output from the passages 241 and 251 will becontrolled by the backloading or the magnitude of the control signalsapplied to the tubes 46V and 47. Also, as discussed in regard to FIGUREl, the sidewalls of the output passages 241 and 251 may be alternativelyset back so that boundary layer effects will be generated and class IIope-ration effected.

Referring now to FlGURE 2 of the accompanying drawings, there is shownanother embodiment of a pure duid amplifier designated by the Vnumeral102, which Q :l basically represents the combination of theaforedescribed pure -uid amplifiers and 101, illustrated respectively inFIGURES 1 and 2 of the accompanying drawings. In

this embodiment, the substantially -cylindrical control" nozzles 142 and152 are provided with tangentially eX- tending passages 432 and 442,respectively, and cusps 412 and 422 respectively that scoop fringeportions of the fiuid rotating in the control nozzles 142 and 152 intothe passages 432 and 442. In addition, orifices 242 and 252 are formedcentrally in the substantially planar bases of the control nozzles 142and 152 to supply 4fiuid input signals to the control nozzles. Theorifices 242 .and 252 have the two tubes 262 and 272 respectivelythreadedly connected therein, and the tubes 282 and 292 are respectivelythreadedly connected into the downstream ends of the passages 432 and442. A T-shaped junction designated -by the numeral 54 joins the tubes262 and 282, through the valves `50 and 51, respectively, and a similarT-shaped junction 5-5 joins the tubes 272 and 292 through valves 52 and53, respectively. The valves Si), 51, 52 and 53 can -be adjusted suchthat the valves 50 and 52 valve a predetermined amount of fiuid into thecontrol nozzles 142 and 152 through the tubes 262 and 272, respectively,and the valves 51 and 53 produce a predetermined backloading pressureagainst fiuid egressing from the passages 432 and 442, respectively.

Input fiuid control signals are supplied to the T-junctions 54 and 55after a predetermined bias or sensitivity has been established byadjustment of the four valves 50, 51, 52 and 53, and as a result apredetermined power stream bias and sensitivity is developed.Thereafter, fiuid input or control signals received by the two junctions54 and 55 will eect amplified displacement of the power jet issuing fromthe power nozzle 132, for reasons discussed hereinabove.

In the aforedescribed three pure fiuid amplifiers, the momentuminterchange that occurs between the substantially cylindrical controlnozzles located tangentially of the sidewalls of the interaction chamberand the power jet minimizes the energy losses which normally result whenthere is direct impingement of a defined control jet against a definedpower jet. Such is the case, for example, in conventional pure fiuidamplifying systems incorporating control nozzles that converge or taperto egress orifices formed in the sidewalls of the interaction chamberadjacent the power nozzle orices. Thus, the instant invention inaddition to providing a predetermined or an adjustable bias andsensitivity to the power stream also reduces the momentum exchangelosses inherent in the stream interaction in conventional pure fiuidamplifiers.

While I have described and illustrated several specific embodiments ofmy invention, it will be clear that variations of the details ofconstruction which are specifically illustrated and described may beresorted to without departing from the true spirit and scope of theinvention as defined in the appended claims.

What I claim is:

1. A pure fluid amplifier comprising an interaction chamber including apair of opposed sidewalls for transversely restricting the movement of afiuid stream, a power nozzle for issuing a power stream into one end ofsaid interaction chamber, at least one chamber of substantiallycylindrical shape with the periphery thereof positioned substantiallytangentially to the surface defining one of said sidewalls, a portformed between said cylindrical chamber and said interaction region as aresult of convergence of the surfaces of said chamber sidewall and saidcylindrical chamber at the point of tangency of said surfaces so thatthe power stream iiowing across said port interacts with fiuid in saidcylindrical chamber and produces unidirectional circulation of fluidtherein, and an ingress passage communicating with said cylindricalchamber for supplying fiuid thereto.

2. The pure fiuid amplifier as claimed in claim 1 wherein twoessentially cylindrical chambers of substantially equal diameter areprovided in substantially opposed relationship with respect to saidinteraction chamber so as to provide ports into said interaction regionon opposite sides of said interaction region.

3. The pure fiuid amplifier as claimed in claim 1 wherein saidcylindrical chamber has a longitudinal axis of symmetry, and wherein anorifice is formed in said cylindrical chamber on said axis, the diameterof said orifice being considerably less than the diameter of saidcylindrical chamber, and wherein said ingress passage is connected tosaid orifice so as to supply fluid to said cylindrical chamber.

4. The pure fluid amplifier as claimed in claim 1 wherein an egresspassage extends substantially tangentially from said cylindrical chamberin the direction of fluid circulation in said cylindrical chamber sothat a portion of the circulating fiuid is received by said egresspassage.

5. The pure fiuid amplifier as claimed in claim 4, wherein means areprovided for regulating the quantity of fiuid supplied to said ingresspassage and, means are provided for regulating the back pressure in saidegress passage.

6. A pure fiuid amplifier comprising an intreaction chamber including apair of opposed sidewalls for transversely restricting the movement of afiuid stream, a power nozzle for issuing a power stream into one end ofsaid interaction chamber, at least one chamber of substantiallycylindrical shape with the periphery thereof positioned substantiallytangentially to the surface defining one of said sidewalls, a portformed between the cylindrical chamber and said interaction region as aresult of convergence of the surfaces of said chamber sidewall and saidcylindrical chamber at a point of tangency of said surfaces so that thepower stream fiowing across said port interacts with fiuid in saidcylindrical chamber and produces unidirectional circulation of fiuidtherein, and an egress passage extending substantially tangentially fromthe periphery of said cylindrical chamber in the direction of fiuidcirculation for receiving a portion of the circulating fiuid therefrom.

7. A pure fiuid amplifier comprising an interaction chamber including apair of opposed sidewalls for transversely restricting the movement of afiuid stream, a power nozzle for issuing a power stream into one end ofsaid interaction chamber, at least one chamber of substantiallycylindrical shape with the periphery thereof positioned substantiallytangentially to the surface defining one of said sidewalls, a portformed between said cylindrical chamber and said interaction region as aresult of convergence of the surfaces of said chamber sidewalls and saidcylindrical chamber at the point of tangency of said Surfaces so thatthe power stream fiowing across said port interacts with fiuid in saidcylindrical chamber and produces circulation of fluid therein, and meansfor controlling defiection of said power stream comprising a passageconnected to said chamber remote from said port and means forcontrolling iiow of fiuid through said passage relative to said chamber.

References Cited UNITED STATES PATENTS 1,381,095 6/1921 Starr 137-8152,841,182 7/1948 Scala 138-39 2,894,703 7/1959 Hazen 137-815 2,910,83011/1959 White 137-815 3,149,783 9/1964 Sosnick 137-815 3,158,166 11/1964Warren 137-815 3,192,938 7/1965 Bauer 137-815 3,195,303 7/1965 Widell137-815 3,208,462 9/1965 Fox 137-815 3,216,439 11/1965 Manion 137-8153,233,621 2/1966 Manion 137-815 M. CARY NELSON, Primary Examiner. W.CLINE, Assistant Examiner.

1. A PURE FLUID AMPLIFIER COMPRISING AN INTERACTION CHAMBER INCLUDING APAIR OF OPPOSED SIDEWALLS FOR TRANSVERSELY RESTRICTING THE MOVEMENT OF AFLUID STREAM, A POWER NOZZLE FOR ISSUING A POWER STREAM INTO ONE END OFSAID INTERACTION CHAMBER, AT LEAST ONE CHAMBER OF SUBSTANTIALLYCYLINDRICAL SHAPE WITH THE PERIPHERY THEREOF POSITIONED SUBSTANTIALLYTANGENTIALLY TO THE SURFACE DEFINING ONE OF SAID SIDEWALLS, A PORTFORMED BETWEEN SAID CYLINDRICAL CHAMBER AND SAID INTERACTION REGION AS ARESULT OF CONVERGENCE OF THE SURFACES OF SAID CHAMBER SIDEWALL AND SAIDCYLINDRICAL CHAMBER AT THE POINT OF TANGENCY OF SAID SURFACES SO THATTHE POWER STREAM FLOWING ACROSS SAID PORT INTERACTS WITH FLUID IN SAIDCYLINDRICAL CHAMBER AND PRODUCES UNIDIRECTIONAL CIRCULATION OF FLUIDTHEREIN, AND AN INGRESS PASSAGE COMMUNICATING WITH SAID CYLINDRICALCHAMBER FOR SUPPLYING FLUID THERETO.